Modified TLS-test slightly: the program checking for TLS support is now compiled, linked and run when compiling natively and compiled and linked only when cross-compiling. Before it was compiled and linked only, both for native and cross-compilation.
git-svn-id: svn://svn.valgrind.org/valgrind/trunk@8172 a5019735-40e9-0310-863c-91ae7b9d1cf9
diff --git a/configure.in b/configure.in
index 5cbae44..1bdbde7 100644
--- a/configure.in
+++ b/configure.in
@@ -1149,6 +1149,19 @@
# Check for TLS support in the compiler and linker
+if test "x${cross_compiling}" = "xno"; then
+# Native compilation: check whether running a program using TLS succeeds.
+# Linking only is not sufficient -- e.g. on Red Hat 7.3 linking TLS programs
+# succeeds but running programs using TLS fails.
+AC_CACHE_CHECK([for TLS support], vg_cv_tls,
+ [AC_ARG_ENABLE(tls, [ --enable-tls platform supports TLS],
+ [vg_cv_tls=$enableval],
+ [AC_RUN_IFELSE([AC_LANG_PROGRAM([[static __thread int foo;]],
+ [[return foo;]])],
+ [vg_cv_tls=yes],
+ [vg_cv_tls=no])])])
+else
+# Cross-compiling: check whether linking a program using TLS succeeds.
AC_CACHE_CHECK([for TLS support], vg_cv_tls,
[AC_ARG_ENABLE(tls, [ --enable-tls platform supports TLS],
[vg_cv_tls=$enableval],
@@ -1156,6 +1169,7 @@
[[return foo;]])],
[vg_cv_tls=yes],
[vg_cv_tls=no])])])
+fi
if test "$vg_cv_tls" = yes; then
AC_DEFINE([HAVE_TLS], 1, [can use __thread to define thread-local variables])